BlockingRpcCallback<MetaDataResponse> rpcCallback =
new BlockingRpcCallback<MetaDataResponse>();
UpdateIndexStateRequest.Builder builder = UpdateIndexStateRequest.newBuilder();
for (Mutation m : tableMetadata) {
MutationProto mp = ProtobufUtil.toProto(m);
builder.addTableMetadataMutations(mp.toByteString());
}
instance.updateIndexState(controller, builder.build(), rpcCallback);
if(controller.getFailedOn() != null) {
throw controller.getFailedOn();
}